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恒荷载效应在土木、水利等大型工程结构的分析中往往占有不可忽略的显著位置。针对传统弹塑性方法分析恒荷载效应显著结构失效模式存在的失效路径依赖性问题,结合截面强度融合技术和弹性模量调整策略,提出恒荷载效应显著结构失效元和失效模式的识别方法,进而建立恒荷载效应显著结构损伤演化和失效模式分析的弹性模量缩减法。首先将恒荷载效应融入构件的截面强度,建立强度和外荷载分布都发生改变的修正结构计算模型;然后根据齐次化广义屈服函数定义单元承载比和基准承载比,建立高承载单元识别的自适应准则;进而通过缩减高承载单元的弹性模量来模拟结构的刚度损伤,并确定结构的极限承载力;最后根据结构进入塑性极限状态时高承载单元的弹性模量缩减幅度批量标示失效元,据此确定结构的失效模式。通过算例分析,验证了该方法具有较强的稳定收敛性,能够取得较高的计算精度和效率,可以更加合理地描述结构的损伤演化过程,具有较强的适用性。
Constant load effect in civil engineering, water conservancy and other large structures often occupy a significant position can not be ignored. According to the traditional elasto-plastic method to analyze the failure path dependence of the significant structural failure modes of the constant load effect, the identification method of significant structural failure elements and failure modes under constant load effect is proposed by combining the cross-section strength fusion technique and the elastic modulus adjustment method, Elastic Modulus Reduction Method for Analysis of Structural Damage Evolution and Failure Modes under Constant Load Effect. Firstly, the constant load effect is incorporated into the cross-sectional strength of the member to establish a modified structure calculation model whose intensity and external load distribution all change. Based on the homogeneous load-yield function, the unit bearing ratio and the reference bearing ratio are defined. Then the stiffness of the structure is simulated by reducing the elastic modulus of the high load-carrying unit and the ultimate bearing capacity of the structure is determined. Finally, according to the reduction of the elastic modulus of the high load-bearing unit when the structure enters the plastic limit state, Accordingly, the failure mode of the structure is determined. Through the example analysis, it is verified that this method has strong and stable convergence, can obtain higher accuracy and efficiency of calculation, and can describe the damage evolution process of structure more reasonably. It has strong applicability.